1. Field of the Invention
The present invention relates to a light emission device.
2. Discussion of the Background
The semiconductor light emitting element is mounted on a supporting substrate, a package, and the like through various methods. The semiconductor light emitting element having positive and negative electrodes on the same surface side is flip-chip mounted by joining the positive and negative electrode side to the supporting substrate etc., so that light can be retrieved from the substrate side of the element. A method of flip-chip mounting the semiconductor light emitting element includes, for example, a method comprising forming a bump on a conductor wiring arranged on a main surface of a supporting substrate capable of mounting the semiconductor light emitting element, facing the electrode surface of the semiconductor light emitting element having a pair of positive and negative electrodes arranged on the same surface side to the bump, and contacting the positive and negative electrodes of the semiconductor element and the bump to join the conductor wiring and the electrodes of the semiconductor light emitting element. The conductor wiring of the supporting substrate and the positive and negative electrodes of the semiconductor light emitting element are joined through the bump in this manner so that they are electrically conducted.
A plurality of semiconductor light emitting elements can be mounted on one light emission device. For example, WO2004/082036, Japanese Laid-Open Patent Publication Nos. 2005-85548, 2005-109434 and 2006-66700 disclose such a light emission device. The contents of these publications are incorporated herein by reference in their entirety. One example is shown in FIG. 20. The light emission device shown in FIG. 20 has a circuit pattern 52 containing W, Ni, and Au on the surface of Al2O3 substrate 51 containing glass, and a total of nine GaN-based LED elements 53 arrayed three by three are flip-chip mounted on the circuit pattern 52 through an Au bump. An electrode structure of the GaN-based LED element 53 is omitted, but is arranged in correspondence to the circuit pattern 52.
In the light emission device flip-chip mounted with the light emitting element, most of the light generated in the light emitting element is exited from the surface on the substrate side or the side surface of the element. The light exited from the end face of the element side surface is generally reflected by a reflection plate etc. arranged in the light emission device, and is retrieved to the light emission observing surface side.
However, some of the light exited from the element end face is absorbed by the supporting substrate, the sealing resin, and the like until reflected with a reflection plate. Thus, in the conventional light emission device, the light from the element end face was attenuated before retrieved as light of the light emission device, and thus did not sufficiently contribute to light emission of the entire light emission device.